How Dangerous Was the Ohio Chemical Train Derailment?

The main concern now is the contamination of homes, soil and water, primarily from volatile organic compounds and semivolatile organic compounds, known as VOCs and SVOCs.

The train had nearly a dozen cars with vinyl chloride and other materials, such as ethylhexyl acrylate and butyl acrylate. These chemicals have varying levels of toxicity and different fates in soil and groundwater. Officials have detected some of those chemicals in the nearby waterway and particulate matter in the air from the fire. But so far, the fate of many of the chemicals is not known. A variety of other materials was also released, but discussion about those chemicals has been limited.

State officials disclosed that a plume of contamination released into the nearby creek had made its way into the Ohio River. Other cities get their drinking water from the river and were warned about the risk. The farther this plume moves downstream, the less concentrated the chemical will be in water, posing less of a risk.

In the long term, the greatest risk is to areas closest to the derailment location. And again, there's limited information about what chemicals are present — or were created through chemical reactions during the fire.

It isn't clear yet how much went into storm drains, was flushed down the streams or may have settled to the bottom of waterways.

There was also a lot of combusted particulate matter. The black smoke is a clear indication. It's unclear how much was diluted in the air or fell to the ground.

The heavier the chemical, often the slower it degrades and the more likely it is to stick to soil. These compounds can remain for years if left unaddressed.

After the Kalamazoo River oil pipeline break in Michigan in 2010, the U.S. Environmental Protection Agency excavated a tributary where the oil settled. We've also seen from oil spills on the coasts of Alaska and Alabama that oil chemicals can find their way into soil if they aren't remediated.

The long-term impact in Ohio will depend in part on how quickly — and thoroughly — cleanup occurs.

If the heavily contaminated soils and liquids are excavated and removed, the long-term impacts can be reduced. But the longer removal takes, the farther the contamination can spread. It's in everyone's best interest to clean this up as soon as possible and before the region gets rain.

Booms in a nearby stream have been deployed to capture chemicals. Air-stripping devices have been deployed to remove chemicals from the waterways. Air stripping causes the light chemicals to leave the water and enter air. This is a common treatment technique and was used after a 2015 oil spill in the Yellowstone River near Glendive, Montana.

At the derailment site in Ohio, workers are already removing contaminated soil as deep as 7 feet (2 meters) near where the rail cars burned.

Incineration is one way we dispose of hazardous chemicals, but incomplete chemical destruction creates a host of byproducts. Chemicals can be destroyed when heated to extremely high temperatures so they burn thoroughly.

The black smoke plume you saw on TV suggests incomplete combustion. A number of other chemicals were created. Officials don't necessarily know what these were or where they went until they test for them.

We know ash can pose health risks, which is why we test inside homes after wildfires where structures burn. This is one reason the state's health director told residents with private wells near and downwind of the derailment to use bottled water until they can have their wells tested.

Homes are not airtight, and sometimes dust and other materials get in. It might be through an open door or a windowsill. Sometimes people track it in.

So far, the U.S. EPA has reported no evidence of high levels of vinyl chloride or hydrogen chloride in the 400 or so homes tested. But full transparency has been lacking. Just because an agency is doing testing doesn't mean it is testing for what it needs to test for.

Media reports talk about four or five chemicals, but the train manifest from Norfolk Southern also listed a bunch of other materials in tanks that burned. All those materials create potentially hundreds to thousands of VOCs and SVOCs.

People in the community have reported headaches, which can be caused by VOCs and other chemicals. Residents are understandably concerned.

Ohio and federal officials need to better communicate what they're doing, why and what they plan to do. It's unclear what questions they are trying to answer. For a disaster this serious, there has been little testing information shared.

In the absence of this transparency, misinformation is filling that void. From a homeowner's perspective, it's hard to understand the true risk if the data is not shared.

Andrew J. Whelton is a professor of civil, environmental and ecological engineering, as well as the director of the Healthy Plumbing Consortium and Center for Plumbing Safety at Purdue University. He receives funding from the U.S. National Science Foundation, the U.S. Environmental Protection Agency, the U.S. Federal Highway Administration, the Water Research Foundation and Purdue University.

This article is republished from The Conversation under a Creative Commons license. You can find the original article here.